I’m a Canon professional photographer, so I'm a big Canon fan and I only shoot with EOS cameras. I still use Canon DSLRs for studio stuff and day-to-day photography when I don’t need an EOS R5 Mark II’s super-fast AI AF and I’m not shooting small moving targets.
But one of the reasons I like using full-frame mirrorless Canon cameras like the R6 Mark III is that they have a clever built-in 1.6x crop mode. I find this useful when I’m traveling light and only have one lens on my camera, such as during a recent city break in Madrid, Spain.